JP7477097B2 - Dissimilar material joint member and manufacturing method thereof - Google Patents

Description

The present invention relates to a dissimilar material joint between a metal material and a resin material and a manufacturing method thereof, and more specifically, to a dissimilar material joint between a porous metal material and a resin material and an efficient manufacturing method thereof.

Porous metals, for which research and development into manufacturing technologies is currently underway, will achieve weight reductions that exceed the limits of dense materials. In recent years, weight reductions have been made through the use of aluminum in automobiles and magnesium in electrical products, but by making metals porous, it is possible to achieve ultra-lightweight products that exceed these limits.

In addition, because porous metals are porous and have a large specific surface area, they are also seen as promising functional materials with high energy absorption capacity, heat exchange capacity, insulation properties, sound absorption properties, etc. Practical development is underway for various automobile parts, as well as shock absorbing materials, soundproofing materials, biomedical materials, etc., but there are many cases where it is difficult to use porous metals alone, and there is a strong demand for bonding technologies to other materials.

In particular, if it is possible to join a lightweight resin material with excellent moldability to a porous metal, the range of uses for the porous metal is expected to expand dramatically. Here, for example, Patent Document 1 (JP 2019-166638 A) discloses a method for manufacturing a resin-metal bonded body formed by joining a resin and an aluminum material, which includes a nano-relief structure production process for producing a nano-relief structure including a large number of holes in the aluminum material, each of which has a surface opening that opens to the surface side of the aluminum material, and a joining process for joining the aluminum material and the resin by infiltrating the molten resin from the surface opening into the holes and then solidifying the resin, and in the nano-relief structure production process, a communication part that communicates with each other is formed inside each of the holes, and an internal space composed of each of these holes and communication parts is formed so as to be openable to the outside at a site other than each of the surface openings of each of the holes.

In the manufacturing method of a resin-metal bonded body described in the above Patent Document 1, a nano-relief structure having a large number of holes arranged irregularly with respect to each other is created on the surface side of the aluminum material that is to be bonded to the resin, and the resin and the aluminum material are bonded by infiltrating the molten resin into each hole and solidifying it. Here, the insides of the holes are in a mutually communicating state via the communicating parts, and the internal space formed by these holes and communicating parts is open at a site other than the surface opening of each hole. Therefore, when the resin infiltrates into each hole from each surface opening, the air in each hole escapes from the open part of the internal space, and the resin can be sufficiently distributed in the internal space. Moreover, since each hole has an irregular shape, the resin filled in the internal space is complicatedly entangled and solidified inside the aluminum material, increasing the bonding area between the aluminum material and the resin, and a strong anchor effect can be obtained. Therefore, according to the present invention, it is said that a bonded body of resin and aluminum material that is firmly bonded can be obtained without using bonding members such as bolts and rivets or adhesives.

JP 2019-166638 A

However, the manufacturing method of a resin-metal bonded body disclosed in the above Patent Document 1 achieves bonding by providing holes in the surface of the metal material, and is a method for bonding a dense metal material and a resin material. Furthermore, in this bonding method, the resin material in a molten state is poured into the hole using a hot plate or the like, and it is extremely difficult to control the amount of resin material that flows in, and essentially the entire area of the hole is filled with resin material.

When joining dense metal and resin materials, where weight reduction is not the primary objective, there is no problem with filling the entire area of the hole with resin, but when trying to reduce the weight of the joined body, it is preferable to limit the amount of resin filling the hole as long as sufficient joining strength is obtained.

In view of the problems with the conventional technology described above, the object of the present invention is to provide a dissimilar material joining method for easily and efficiently forming a strong joint with a resin material without compromising the advantage of porous metal materials in terms of weight reduction, and to provide a dissimilar material joint member having high joint strength obtained by the method.

In order to achieve the above objective, the inventors conducted extensive research into methods for joining dissimilar materials, such as porous metal and resin materials, and discovered that using the frictional heat generated at the contact surface between the porous metal and resin materials is extremely effective, leading to the creation of this invention.

That is, the present invention provides:
A method for directly bonding a porous metal material to a resin material, comprising:
The porous metal material has a porosity of 30 to 95 volume % and has open pores on the joining surface,
the area ratio of the open pores on the bonded surfaces is 30 to 95%,
a first step of contacting the porous metal material with the resin material to form a joining interface;
a second step of generating frictional heat in the vicinity of the interface to be joined by sliding between the porous metal material and the resin material, and impregnating the resin material softened or melted by the frictional heat into the open pores;
The present invention provides a method for joining dissimilar materials, comprising the steps of:

The dissimilar material joining method of the present invention preferably further includes a third step of promoting the impregnation of the resin material softened or melted by the frictional heat into the open pores. In the third step, the impregnation of the resin material can be promoted by reducing the sliding speed or stopping the sliding in the second step, or by reducing the pressing force that brings the interfaces to be joined together, and maintaining these conditions for a certain period of time.

As long as the porosity is 30-95% by volume, the surfaces to be joined have open pores, and the area ratio of the open pores on the surfaces to be joined is 30-95%, the material and structure of the porous metal are not particularly limited, and various conventionally known porous metals can be used. For example, the porous metal may be an open-cell type or a closed-cell type.

In the dissimilar material joining method of the present invention, frictional heat is generated near the interface between the porous metal material and the resin material by sliding between them, and the resin material softened or melted by the frictional heat is impregnated into the open pores, preventing the resin material from being filled more than necessary, while the application of a pressing force firmly joins the filled resin material and the porous metal material.

In addition, in the dissimilar material joining method of the present invention, it is preferable that in the second step and/or the third step, the porous metal material is pressed into the resin material by 5 μm to 1 mm. By pressing the porous metal material into the resin material by 5 μm or more, a joining region with a thickness equivalent to at least one open pore can be formed. Furthermore, by setting the pressing amount to 1 mm or less, it is possible to suppress the formation of a joining region that is thicker than necessary and prevent an increase in the weight of the joined body due to a reduction in pores.

In addition, in the dissimilar material joining method of the present invention, it is preferable that the porous metal material and the resin material are subjected to rotational or linear sliding in the second step. By subjecting the porous metal material and the resin material to rotational or linear sliding, the resin material softened or melted by frictional heat can be efficiently and easily impregnated into the open pores. Here, the method of subjecting the porous metal material and the resin material to rotational or linear sliding is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known methods can be used. For example, in the case of rotational sliding, a friction welding device can be preferably used, and in the case of linear sliding, a linear friction joining device can be preferably used.

In addition, in the dissimilar material joining method of the present invention, it is preferable that the average diameter of the open pores in the joined surfaces is 5 μm to 5 cm. By setting the average diameter of the open pores contributing to the joining to 5 μm to 5 cm, it is possible to simultaneously achieve smooth impregnation of the resin material and ensure the joining strength due to the impregnation of the resin material.

In addition, in the dissimilar material joining method of the present invention, it is preferable that the porous metal material is a porous aluminum material or a porous magnesium material. Aluminum and magnesium materials are lightweight and have excellent mechanical properties and formability, and can be used for a wide variety of purposes by joining them with resin materials.

Furthermore, in the dissimilar material joining method of the present invention, it is preferable that the resin material is a fiber reinforced plastic (FRP) material. Fiber reinforced plastic (FRP) has high mechanical properties and reliability as a structural material, and by joining it with a porous metal material, it can be suitably used, for example, as a structural member that requires light weight and high strength. It is more preferable to use carbon fiber reinforced plastic (CFRP) as the fiber reinforced plastic (FRP).

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
A joining member in which a porous metal material and a resin material are directly joined,
The porous metal material has open pores with an average diameter of 5 μm to 5 cm and a porosity of 30 to 95 vol. %,
a bonding region formed by impregnating the open pores with the resin material;
The thickness of the bonding area is 5 μm to 1 mm;
The present invention also provides a dissimilar material joining member, characterized in that

The dissimilar material joining member of the present invention has a porosity of 30 to 95 volume percent for the porous metal, which is significantly lighter than dense metal materials. In addition, it has open pores with an average diameter of 5 μm to 5 cm that contribute to joining with the resin material, and has a joining region in which the open pores are impregnated with the resin material. The porous metal may be either an open cell type or a closed cell type.

In addition, by making the thickness of the joint area 5 μm or more, sufficient joint strength can be achieved, and by making it 1 mm or less, the weight increase of the dissimilar material joint component is suppressed.

In addition, in the dissimilar material joining member of the present invention, it is preferable that the porous metal material is a porous aluminum material or a porous magnesium material. In addition to being lightweight, aluminum and magnesium materials have excellent mechanical properties and formability, and can be used for a wide variety of purposes by joining them with a resin material.

In addition, in the dissimilar material joining member of the present invention, it is preferable that the resin material is a fiber reinforced plastic (FRP) material. Fiber reinforced plastic (FRP) has high mechanical properties and reliability as a structural material, and by joining it with a porous metal material, it can be suitably used, for example, as a structural member that requires light weight and high strength. It is more preferable to use carbon fiber reinforced plastic (CFRP) as the fiber reinforced plastic (FRP).

Furthermore, in the dissimilar material joining member of the present invention, it is preferable that the porous metal material is a porous metal plate material, the resin material is a resin plate material, and the resin plate material is joined to the front and/or back surface of the porous metal plate material. By firmly bonding the resin material to the front and/or back surface of the porous metal material, it can be used extremely suitably as a lightweight, high-strength structural material.

The dissimilar material joining member of the present invention can be obtained simply and efficiently by the dissimilar material joining method of the present invention.

The present invention provides a dissimilar material joining method for easily and efficiently forming a strong joint with a resin material without compromising the weight-saving advantage of porous metal materials, and a dissimilar material joint member having high joint strength obtained by the method.

1 is a schematic diagram showing a joining process of a method for joining dissimilar materials according to the present invention; 1 is a schematic cross-sectional view of a dissimilar material joint member showing one embodiment of the present invention. 1 is a photograph showing the arrangement of a porous aluminum material and an acrylic resin plate in an embodiment. 1 is a photograph showing a state in which a porous aluminum material is pressed into and held in an acrylic resin plate in an embodiment. 1 is a photograph showing the state after bonding in an embodiment. The graph shows the bonded surface of a dissimilar material bonded member obtained with a holding time of 30 seconds and a fracture surface after a tensile test. Photographs of the bonded surface of a dissimilar material bonded member obtained with a holding time of 15 seconds and its appearance after a tensile test are shown.

Below, we will explain in detail typical embodiments of the dissimilar material joining method of the present invention and the dissimilar material joined member obtained thereby with reference to the drawings, but the present invention is not limited to these. In the following explanation, the same or equivalent parts are given the same reference numerals, and duplicate explanations may be omitted. In addition, since the drawings are intended to conceptually explain the present invention, the dimensions of each component shown and their ratios may differ from the actual ones.

(1) Method for joining dissimilar materials The method for joining dissimilar materials of the present invention is a method for directly joining a porous metal material and a resin material, characterized in that frictional heat is generated in the vicinity of the joined interface by sliding between the porous metal material and the resin material, and the resin material softened or melted by the frictional heat is impregnated into the open pores.

(1-1) Materials to be joined The porous metal material used in the method for joining dissimilar materials of the present invention has a porosity of 30 to 95% by volume, has open pores on the surfaces to be joined, and the area ratio of the open pores on the surfaces to be joined is 30 to 95%. The porosity is preferably 50 to 90%, and more preferably 60 to 80%. With the porosity in this range, it is possible to achieve both weight reduction and high levels of mechanical properties. With the open pores contributing to the joining in this range, it is possible to obtain high joining strength and form a homogeneous joining region.

Porous metals come in open cell and closed cell types, and either can be used. If there are no open pores on the surfaces to be joined, a suitable cross section can be used as the surface to be joined, and the area ratio of the open pores on that cross section can be adjusted to 30-95%.

The average diameter of the pores in the porous metal is preferably 5 μm to 5 cm, and more preferably 200 μm to 2 cm, whether the pores are of the open-cell type or the closed-cell type. If there are no open pores on the surfaces to be joined, they can be used for joining by cutting them at an appropriate cross section to create open pores.

In addition, the material of the porous metal is not particularly limited as long as it does not impair the effects of the present invention, and for example, aluminum, magnesium, titanium, nickel, copper, steel, stainless steel, etc. can be used. Here, from the viewpoint of weight reduction, it is preferable to use aluminum.

The resin material used in the dissimilar material joining method of the present invention is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known resin materials can be used, but it is preferable to use a thermoplastic resin material that softens and/or melts due to frictional heat. In addition, from the viewpoint of ensuring strength and reliability as a structural member, it is preferable to use fiber reinforced plastic (FRP), and it is more preferable to use carbon fiber reinforced plastic (CFRP).

(1-2) Joining method In the method for joining dissimilar materials of the present invention, frictional heat is generated near the interface between the porous metal material and the resin material by sliding between them, and the following will be described in detail as a representative example of the case where a porous metal material and a resin material are rotated and slid. A schematic diagram of the joining process in the method for joining dissimilar materials of the present invention is shown in Figure 1.

(A) First Step In the first step, the porous metal material 2 and the resin material 4 are brought into contact with each other to form a joining interface 6. At this time, the porous metal material 2 and the resin material 4 may be brought into contact with each other while both or either one of them is rotated, or both may be brought into contact with each other without being rotated.

It is also preferable that the porous metal material 2 and the resin material 4 are brought into contact with each other with a pressure that does not deform the porous metal material 2 and the resin material 4, and that the joining interface 6 is formed so that the joining surfaces of the porous metal material 2 and the resin material 4 are evenly in close contact with each other.

(B) Second step In the second step, frictional heat is generated near the joining interface 6 by sliding between the porous metal material 2 and the resin material 4. Here, a case where only the porous metal material 2 is rotated will be described, but the porous metal material 2 rotated at an appropriate rotation speed is pressed into the resin material 4 by controlling the position of the porous metal material 2 or controlling the load applied to the porous metal material 2, thereby generating frictional heat.

In the second step, it is preferable to press the porous metal material 2 into the resin material 4 by 5 μm to 1 mm. By pressing the porous metal material 2 into the resin material 4 by 5 μm or more, at least an amount of the resin material 4 that contributes to the bonding strength is filled into the open pores, and a good bonding region can be formed. Furthermore, by setting the pressing amount to 1 mm or less, it is possible to suppress the formation of a bonding region that is thicker than necessary and prevent an increase in the weight of the bonded body due to a reduction in pores.

When the resin material 4 is melted by external heating and impregnated into the open pores of the porous metal material 2, the open pores are filled with more resin material 4 than necessary, reducing the advantages of the porous structure of the porous metal material 2. In contrast, when sliding between the porous metal material 2 and the resin material 4 is used, it is easy to control the area (thickness) where the resin material 4 is softened or melted, and a joining area with the desired thickness can be formed by adjusting the sliding speed, amount of pressure, etc.

(C) Third step The third step is not essential, but it can promote the impregnation of the resin material softened or melted by frictional heat into the open pores present at the interface to be joined. In the second step, the resin material softened or melted by frictional heat also impregnates the open pores, but the third step is a step for promoting the impregnation. For example, when the porous metal material 2 is frictionally welded to the resin material 4 by position control, the impregnation of the resin material can be promoted by holding the porous metal material 2 at a predetermined position for a certain period of time after reaching a predetermined amount of press-in (joining position). In addition, when the porous metal material 2 is frictionally welded to the resin material 4 by load control, the impregnation of the resin material can be promoted by lowering the pressure applied to the porous metal 2 and holding the pressure for a certain period of time after reaching a predetermined amount of press-in (joining position).

The holding time at the joining position may be adjusted as appropriate depending on the material, porosity, size of the open pores, area ratio of the open pores, and material of the resin material 4 of the porous metal material 2. The porous metal material 2 may be held in a rotating state, or may be held with the rotation of the porous metal material 2 stopped.

(2) Dissimilar material joint member A schematic cross-sectional view of a dissimilar material joint member showing one embodiment of the present invention is shown in Fig. 2. The dissimilar material joint member 10 of the present invention is a joint member in which a porous metal material 2 and a resin material 4 are directly joined, and has a joint region 12 in which the resin material 4 is impregnated into the open pores of the porous metal material 2. In other words, the dissimilar material joint member 10 is not one in which the porous metal material 2 and the resin material 4 are indirectly joined by, for example, an adhesive or the like.

The thickness of the joining region 12 is 5 μm to 1 mm, and is preferably 100 to 800 μm, and more preferably 200 to 700 μm. By setting the thickness of the joining region 12 within this range, it is possible to achieve both high joining strength that breaks the base material in a tensile test and suppression of weight increase of the dissimilar material joining member 10.

The porous metal material 2 has a porosity of 30 to 95% by volume. The porosity is preferably 50 to 90%, and more preferably 60 to 80%. With a porosity in this range, it is possible to achieve both lightweight and high levels of mechanical properties.

Porous metals come in open cell and closed cell types, and either may be used for the porous metal material 2. If there are no open pores on the surfaces to be joined, a suitable cross section can be used as the surface to be joined, and the area ratio of the open pores on that cross section can be adjusted to 30 to 95%.

The average diameter of the pores in the porous metal material 2 is preferably 5 μm to 5 cm, and more preferably 200 μm to 2 cm, regardless of whether the pores are of the open cell type or closed cell type. A joining region 12 is formed in which the resin material 4 is filled into the open pores present on the joining surfaces.

In addition, the material of the porous metal material 2 is not particularly limited as long as it does not impair the effects of the present invention, and for example, aluminum, magnesium, titanium, nickel, copper, steel, stainless steel, etc. can be used. Here, from the viewpoint of weight reduction, it is preferable to use aluminum or magnesium.

The resin material 4 is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known resin materials can be used, but it is preferable to use a thermoplastic resin material that softens and/or melts due to frictional heat. In addition, from the viewpoint of ensuring strength and reliability as a structural member, it is preferable to use fiber reinforced plastic (FRP), and it is more preferable to use carbon fiber reinforced plastic (CFRP).

In the dissimilar material joining member 10, the size and shape of the porous metal material 2 and the resin material 4, the location where the joining region 12 is formed, etc. are not particularly limited, but it is preferable that the porous metal material 2 is a porous metal plate material, the resin material 4 is a resin plate material, and the resin plate material is joined to the front and/or back surface of the porous metal plate material. By firmly bonding the resin material 4 to the front and/or back surface of the porous metal material 2, it can be used extremely suitably as a lightweight, high-strength structural material. Here, when joining the porous metal plate material and the resin plate material, linear friction joining, in which they slide linearly, can be suitably used.

The above describes representative embodiments of the present invention, but the present invention is not limited to these, and various design modifications are possible, all of which are included in the technical scope of the present invention.

<Preparation of porous metal materials>
Pure aluminum powder (particle size: about 20 μm) and NaCl powder (particle size: 300 to 425 μm) were used as starting materials. A mixture of the pure aluminum powder and the NaCl powder was prepared so that the porosity of the porous aluminum was 70%.

The prepared mixed powder was filled into a graphite mold and subjected to spark plasma sintering. After sintering, the porous aluminum was removed from the graphite mold and washed with water to remove the NaCl spacer, yielding a disk-shaped porous aluminum with an open cell structure and a diameter of 20 mm. The porous aluminum is an open-cell type porous metal, and pores are formed that basically correspond to the size and shape of the NaCl powder.

<Joining porous metal and resin materials>
A porous aluminum material and an acrylic resin plate (50 mm long x 50 mm wide x 5 mm thick) were joined using the method shown in Figure 1. Specifically, the porous aluminum material was attached to an iron bar (φ20 mm) using a structural adhesive, and the iron bar was attached to the main shaft of a general-purpose friction welding device. The acrylic resin plate was fixed with a vice in a position opposite the porous aluminum material.

The iron bar with the porous aluminum material attached to the tip was rotated at 700 rpm, and the porous aluminum material was brought into contact with the surface of the acrylic resin plate (first step), after which the porous aluminum material was pressed into the acrylic resin plate by 0.5 mm (second step), and this state was maintained for 30 or 15 seconds (third step). After this state was maintained, the iron bar was raised while still rotating.

Figure 3 shows a photograph of the porous aluminum material and acrylic resin plate in place (before bonding), Figure 4 shows a photograph of the porous aluminum material pressed 0.5 mm into the acrylic resin plate to hold it in place, and Figure 5 shows a photograph of the situation after bonding.

Evaluation
A tensile test was carried out on the obtained dissimilar material joint member at a tensile speed of 1 mm/min, and the fracture surface was observed.

Figure 6 shows the joint surface of a dissimilar material joint obtained with a holding time of 30 seconds and the fracture surface after a tensile test. The joint surface was observed from the acrylic resin plate side. It can be seen that the center of the joint surface is black, with the outside of that also blackening in a circular pattern. This blackened area is thought to be the area where a strong joint was formed. It can also be seen that the center and its surrounding area are gouged out on the fracture surface of the porous aluminum material. It can also be seen that the porous aluminum material is attached to the resin on the fracture surface of the resin. These observation results mean that a good bond was achieved that caused the base material to fracture in the tensile test.

Figure 7 shows a photograph of the joint surface of the dissimilar material joint obtained with a holding time of 15 seconds and the appearance after the tensile test. The joint surface and appearance were observed from the acrylic resin plate side. It can be seen that a wide area in the center of the joint surface is blackened. As with the case of a holding time of 30 seconds, it is believed that the porous aluminum material and the acrylic resin plate are firmly bonded in this area. In addition, in the external photograph, it can be seen that the acrylic resin plate has cracked and broken. This occurred before the porous aluminum material and the acrylic resin material broke during the tensile test, indicating that the bond in the center was extremely strong.

2...Porous metal material,
4...Resin material,
6...interface to be joined,
10... Dissimilar material joining member,
12...Joint area.

Claims (11)

A method for directly bonding a porous metal material to a resin material, comprising:
The porous metal material has a porosity of 30 to 95 volume % and has open pores on the joining surface,
the area ratio of the open pores on the bonded surfaces is 30 to 95%,
a first step of contacting the porous metal material with the resin material to form a joining interface;
a second step of generating frictional heat in the vicinity of the interface to be joined by sliding between the porous metal material and the resin material, and impregnating the resin material softened or melted by the frictional heat into the open pores;
A method for joining dissimilar materials, comprising: Further, the present invention includes a third step of promoting the impregnation of the resin material softened or melted by the frictional heat into the open pores.
The method for joining dissimilar materials according to claim 1 , In the second step and/or the third step, the porous metal material is press-fitted into the resin material by 5 μm to 1 mm;
The method for joining dissimilar materials according to claim 1 or 2, In the second step, the porous metal material and the resin material are subjected to rotational or linear sliding;
The method for joining dissimilar materials according to any one of claims 1 to 3, characterized in that the open pores on the bonded surfaces have an average diameter of 5 μm to 5 cm;
The method for joining dissimilar materials according to any one of claims 1 to 4, characterized in that The porous metal material is a porous aluminum material or a porous magnesium material;
The method for joining dissimilar materials according to any one of claims 1 to 5, characterized in that The resin material is a fiber reinforced plastic (FRP) material;
The method for joining dissimilar materials according to any one of claims 1 to 6, characterized in that A joining member in which a porous metal material and a resin material are directly joined,
The porous metal material has open pores with an average diameter of 5 μm to 5 cm and a porosity of 30 to 95 vol. %,
a bonding region formed by impregnating the open pores with the resin material;
The thickness of the bonding area is 5 μm to 1 mm;
A dissimilar material joining component characterized by the above. The porous metal material is a porous aluminum material or a porous magnesium material;
The dissimilar material joint member according to claim 8 . The resin material is a fiber reinforced plastic (FRP) material;
The dissimilar material joint member according to claim 8 or 9, The porous metal material is a porous metal plate material,
The resin material is a resin plate material,
The resin plate is bonded to the front and/or back surface of the porous metal plate;
The dissimilar material joint member according to any one of claims 8 to 10, characterized in that